China reports world’s first human case of bird flu strain H10N3

The man was hospitalised on April 28 after developing a fever and other symptoms

A41-year-old man in China's eastern province of Jiangsu has been confirmed as the first human case of infection with the H10N3 strain of bird flu, China's National Health Commission (NHC) said on Tuesday.

The man, a resident of the city of Zhenjiang, was hospitalised on April 28 after developing a fever and other symptoms, the NHC said in a statement.

He was diagnosed as having the H10N3 avian influenza virus on May 28, it said, but did not give details on how the man had been infected with the virus. The man was stable and ready to be discharged from hospital. Medical observation of his close contacts had not found any other cases.

H10N3 is a low pathogenic, or relatively less severe, strain of the virus in poultry and the risk of it spreading on a large scale was very low, the NHC added. The strain is "not a very common virus," said Filip Claes, regional laboratory coordinator of the Food and Agriculture Organization's Emergency Centre for Transboundary Animal Diseases at the Regional Office for Asia and the Pacific.

Only around 160 isolates of the virus were reported in the 40 years to 2018, mostly in wild birds or waterfowl in Asia and some limited parts of North America, and none had been detected in chickens so far, he added.

China's National Health Commission did not elaborate on how a 41-year-old man from Zhenjiang city had got infected with the H10N3 strain of bird flu. Analysing the genetic data of the virus will be necessary to determine whether it resembles older viruses or if it is a novel mix of different viruses, Claes said.

Many different strains of avian influenza are present in China and some sporadically infect people, usually those working with poultry. There have been no significant numbers of human infections with bird flu since the H7N9 strain killed around 300 people during 2016-2017.

No other cases of human infection with H10N3 have previously been reported globally, the NHC said. H5N8 is a subtype of the Influenza A virus (also known as the bird flu virus). While H5N8 only presents a low risk to humans, it is highly lethal to wild birds and poultry. In April, a highly pathogenic H5N6 avian flu was found in wild birds in northeast China's Shenyang city.